Voters in three states approved marriage for same-sex couples for the first time in history. In a fourth state, a measure to ban gay marriage was defeated.

Prior to Tuesday, same-sex couples had come up short more than 30 times at the ballot box in their efforts to win the right to marry. The movement had won victories in five state legislatures and four state Supreme courts, but had yet to notch a victory at the polls.

When the votes were tallied two states -- Maine and Maryland -- had legalized same-sex marriage for the first time in the nation's history, Minnesota had defeated a constitutional amendment banning it, and Washington appeared to be poised to extend marriage rights to gays and lesbians. In short, it appears that proponents will come away from the night with a clean sweep of all four states voting on the issue.

Leading into the election, opponents in two states -- Maryland and Washington -- had collected enough signatures to give voters the opportunity to overturn laws legalizing same-sex marriage that their legislatures had passed earlier this year. Though polling throughout the campaign season showed voters leaning towards passage by margins as great as 10 percent, the final margins of victory were much slimmer.

In Maine, 53 percent of voters approved the measure, with 47 percent opposing the initiative allowing same-sex partners to marry starting in early December. Maryland's Question 6 calling for legaization of gay marriage passed with 52 percent of the vote. The Maryland law will go into effect on Jan. 1, 2013.

While the outcome of Washington state's Referendum 74 is yet undecided a day after the election, the measure is leading with 52 percent approving and 48 percent opposed, with 51 percent of the precincts reporting, CNN reported.

It should be noted that none of the measures that legalize same-sex marriage require individuals or religious organizations to perform or host any marriage in violation of their religious beliefs.

Minnesota voters were faced with a different vote as opponents of same-sex marriage looked to make an already existing ban on it part of the state constitution. Because the measure involves a change to the constitution it required a 50 percent yes vote to pass, rather than a simple majority. The measure was defeated with 51 percent of the electorate voting no.

This string of victories for same-sex marriage may be indicative of what many analysts are hailing as a dramatic shift in voter attitudes on the issue. In 2001 a Pew Forum poll showed that Americans were opposed to same-sex marriage by a margin of 57 percent to 35 percent. Just 10 years later those numbers have shifted to show that 48 percent now approve of it, while 44 percent oppose it. Eight states now allow same-sex marriage and Washington could be the ninth.